To provide the structure of a differential pressure sensor that is suited for obtaining an accurate pressure signal and can be manufactured easily and a method for assembling the sensor.

A semiconductor chip 1 with a pressure-sensitive part, a fixing stand 2 where a thin part 11 is provided at an outer periphery and the outer- periphery part of the thin part 11 is formed in perpendicular direction, and a housing 4 where a guide part 28 for determining a position for fixing the fixing stand 2 is formed are joined. The semiconductor chip 1 and the fixing stand 2 are joined as an assembly body, and the assembly body is incorporated into the guide part 28 of the housing 4. The peripheral part of the fixing stand 2 and the above housing 4 are joined from a direction where the above assembly body is incorporated, thus facilitating a process for manufacturing a differential pressure sensor extremely and improving yield and quality.